Commercial ceramic and glassware is often decorated by applying a pattern in colored ink on the surface of the substrate with screen printing, offset printing, or any other direct application technique. The glass is then baked at high temperatures to bond the design or indicia to the glass surface. This process, sometimes referred to as applied ceramic labeling (ACL), exhibits certain drawbacks. Often, the ink compositions contain heavy metals and volatile organic solvents (VOC's). Both VOC's and heavy metals are undesirable from the environmental point of view. Second, ACL requires high temperature ovens for the baking step, which results in considerable energy usage and an increased potential for worker injury due to the high temperatures at which the process operates. Moreover, the high temperature ovens are expensive, cumbersome pieces of equipment which require considerable floor space in factories.
The decoration of glass with ultraviolet (UV) radiation curable organic pigmented inks for the decoration of glass and ceramic ware is known in the art. Organic inks generally can be cured by exposure to radiation, such as ultraviolet radiation, thus obviating the need for high temperature baking. In addition, UV curable organic inks can be formulated to contain little or no VOC's or other nonaqueous solvents. Organic inks generally exhibit excellent adherence to glass.
In many countries, it is mandatory that beverages such as beer and soda, be marketed in returnable glass bottles. After the beverage has been consumed, the glass bottles are returned to the beverage filler. They are then cleaned, sterilized, refilled, relabeled, then sold again. Decals and paper labels are most often used to decorate returnable beverage bottles. Both types of labels have many drawbacks. For example, both paper labels and decals are expensive. In addition, they are messy, and can easily come off upon exposure to water or other materials. In addition, many of the adhesives used in decals become sticky when subjected to the bottle cleaning process, and cause machines, drains, etc. to be gummed up.
There is a need for a method to decorate returnable beverage bottles that provides excellent decorative effect. In addition, the method must be cost competitive when compared to paper labels and decals. At the same time the decorative indicia applied should be easily strippable from the glass container between fillings.